The assessment of coronary artery disease in patients with end-stage renal disease

Coronary Artery Disease in Patients on Dialysis: Impact of Traditional Risk Factors

Background and Objectives: End-stage kidney disease (ESKD) is a major risk factor for cardiovascular morbidity and mortality. This study aims to evaluate the contribution of traditional risk factors to the development of coronary artery disease (CAD) in patients on dialysis. Materials and Methods: In this study, 54 patients on dialysis with angina symptoms or a positive exercise stress test underwent coronary angiography. Lesions with obstruction >70% lumen diameter of the coronary artery were considered significant. Traditional risk factors included hypertension, diabetes, smoking, dyslipidemia, age, gender, and time spent on dialysis. Results: Out of 54 participants, 41 (75.92%) were men and 13 (24.07%) women. CAD was present in 34 (62.96%) patients, and 20 (37.03%) patients were without CAD. The average age of the participants was 66.51 years. In the group with CAD, the average age was 69.52 years with an average time spent on dialysis of 2.73 years. In the group without CAD, the average age was 61.40 years with a time spent on dialysis of 2.35 years. Hypertension was present in 92.59% of all participants and 97.05% of those with CAD. Diabetes was present in 41.17 patients with CAD and 40% of those without CAD. Dyslipidemia was present in 76.47 participants with CAD and in 40% of those without CAD. Smoking was noticed in 35.29% of the participants with CAD and 57.14% of those without CAD. Besides hypertension, significant predictors for the development of CAD in patients on dialysis were dyslipidemia (OR 3.698, Cl 1.005-13.608, p = 0.049) and age (OR 1.056, Cl 1.004-1.110, p = 0.033). Conclusions: Among the traditional risk factors, hypertension, dyslipidemia, and age are the predictors for the development of CAD in patients on dialysis. Further large randomized clinical studies are needed to clarify the role of traditional risk factors for CAD in patients with ESKD.

Coronary Artery Disease Assessment and Cardiovascular Events in Middle-Aged Patients on Hemodialysis

OBJECTIVE

To explore whether, in younger patients on dialysis with longer life expectancy, assessment of coronary artery disease (CAD) could identify individuals at higher risk of events and revascularization might improve outcomes in selected patients contrary to what had been observed in elderly patients.

METHODS

From August 1997 to January 2019, 2265 patients with stage 5 chronic kidney disease were prospectively referred for cardiovascular assessment. For this study, we selected 1374 asymptomatic patients aged between 18 and 64 years. After clinical risk stratification and cardiac scintigraphy by single-photon emission computed tomography, 866 patients underwent coronary angiography. The primary end point was the composite incidence of nonfatal/fatal major adverse cardiovascular events during a follow-up period of 0.1 to 189.7 months (median, 26 months). The secondary end point was all-cause mortality.

RESULTS

The primary end point occurred in 327 (23.8%) patients. Clinically stratified high-risk patients had a 3-fold increased risk of the primary end point. The prevalence of abnormal findings on perfusion scans was 29.2% (n=375), and significant CAD was found in 449 (51.8%) of 866 patients who underwent coronary angiography. An abnormal finding on myocardial perfusion scan and the presence of CAD were significantly associated with a 74% and 22% increased risk of cardiovascular events, respectively. In patients undergoing percutaneous coronary intervention or coronary artery bypass grafting (n=99), there was an 18% reduction in the risk of all-cause death relative to patients receiving medical treatment (P=.03).

CONCLUSION

In this cohort of middle-aged, asymptomatic patients on dialysis, assessment of CAD identified individuals at higher risk of events, and coronary intervention was associated with reducing the risk of death in selected patients.

Findings of Cardiovascular Workup of Kidney Transplant Candidates: A Retrospective Study of a Single-Center in Saudi Arabia

Background

There are limited data about the prevalence of cardiovascular (CV) risk factors and the findings of CV workup among kidney transplant (KTx) recipients (KTRs) in Saudi Arabia.

Methods

A single-center retrospective study of KTRs who underwent KTx from 2017 to 2020 was performed. We reviewed the prevalence of CV risk factors and the results of the pre-KTx CV workup which was derived from the American Heart Association guidelines.

Results

We included 254 KTRs. The mean age was 43.1 ± 15.9 years, and 55.5% were men and 79.5% were living-donor KTRs. Pre-emptive KTx was 9.8%, peritoneal dialysis was 11.8%, and hemodialysis was 78.3% (arteriovenous fistula: 33.1% versus hemodialysis catheter: 66.9%). The mean dialysis vintage was 4.8 ± 3.3 years for deceased-donor KTRs versus 2.4 ± 2.6 years for living-donor KTRs. CV risk factors were hypertension: 76%, diabetes: 40.6% (type 1 : 25.2% versus type 2 : 74.7%), hyperlipidemia (low-density lipoprotein >2.6 mmol/L): 40.2%, coronary artery disease (CAD): 12.6%, smoking: 9.1%, peripheral vascular disease: 2.8%, and cerebral vascular disease: 2.4%. The prevalence of obesity stage 1 was 19.7% and obesity stage 2 was 4%. Left ventricular hypertrophy was present in 38.5%. The ejection fraction was abnormal (<55%) in 22%. Abnormal wall motion was present in 34 patients (13.4%). A cardiac (PET-CT) stress test was conducted on 129 patients (50.8%) which showed abnormal perfusion in 37 patients (28.7%). Out of those who required PET-CT, 18.6% had a coronary artery calcium scoring (CACS) of more than 400, 41.8% had a CACS of zero, 29.4% had a CACS of 1-100, and 14.7% had a CACS of 100-400. Coronary angiogram was required in only 41 patients (16.1%), 12 (29.3%) required coronary interventions, 25 (61%) were treated medically, and 4 (9.8%) did not have any CAD. CT scans of pelvic arteries were performed in 118 patients (46.5%). It showed moderate or severe calcifications in only 7 patients (5.9%), whereas it was normal in 97 patients (82.2%), or it showed only mild calcifications in 14 patients (11.9%).

Conclusion

This study outlines the prevalence of CV risk factors and the findings of the pretransplant CV workup among KTx candidates who underwent KTx. Multicenter national studies will be helpful to validate the generalizability of these findings.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Findings of Cardiovascular Workup of Kidney Transplant Candidates: A Retrospective Study of a Single-Center in Saudi Arabia.. [DOI: 10.21203/rs.3.rs-3030184/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: There are limited data about the prevalence of cardiovascular (CV) risk factors and the findings of CV workup among kidney transplant (KTx) recipients (KTRs) in Saudi Arabia. Method: A single-center retrospective study of KTRs who underwent KTx from 2017 to 2020. We reviewed the prevalence of CV risk factors and the results of the pre-KTx CV workup which was derived from the American Heart Association guidelines. Results: We included 254 KTRs. The mean age was 43.1±15.9 years, 55.5% were men and 79.5% were living-donor KTRs. Pre-emptive KTx was 9.8%, peritoneal dialysis: 11.8% and hemodialysis: 78.3% (arteriovenous fistula: 33.1% versus hemodialysis catheter: 66.9%). Mean dialysis vintage was 4.8±3.3 years for deceased-donor KTRs versus 2.4±2.6 years for living-donor KTRs. CV risk factors were hypertension: 76%, diabetes: 40.6% (type 1: 25.2% versus type 2: 74.7%), hyperlipemia (low-density lipoprotein> 2.6 mmol/L): 40.2%, coronary artery disease (CAD): 12.6%, smoking: 9.1%, peripheral vascular disease: 2.8%, and cerebral vascular disease: 2.4%. The prevalence of obesity stage 1 was 19.7% and obesity stage 2 was 4%. Left ventricular hypertrophy was present in 38.5%. Ejection fraction was abnormal (<55%) in 22%. Abnormal wall motion was present in 34 patients (13.4%). Cardiac (PET-CT) stress test was indicated in 129 patients (50.8%) and showed abnormal perfusion in 37 patients (28.7%). Out of those who required PET-CT, 18.6% had coronary artery calcium scoring (CACS) more than 400, 41.8 had CACS of zero, 29.4% had CACS of 1-100, and 14.7% had CACS of 100-400. Coronary angiogram was required in only 41 patients (16.1%), 12 (29.3%) required coronary interventions, 25 (61%) were treated medically, and 4 (9.8%) did not have any CAD. CT scans of pelvic arteries were performed in 118 patients (46.5%). It showed moderate or severe calcifications in only 7 patients (5.9%), whereas it was normal in 97 patients (82.2%), or it showed only mild calcifications in 14 patients (11.9%). Conclusion: This study outlines the prevalence of CV risk factors and the findings of the pretransplant CV workup among KTx candidates who underwent KTx. Multicenter national studies will be helpful to validate the generalizability of these findings.

The Controversies of Coronary Artery Disease in End-Stage Kidney Disease Patients: A Narrative Review

Cardiovascular disease (CVD) accounts for more than 50% of deaths among patients with end-stage kidney disease (ESKD). Approximately 40-50% of ESKD patients have clinically significant coronary artery disease (CAD) due to atherosclerosis which accounts for a significant proportion of CVD risk. However, other CVD pathologies including myocardial fibrosis, vascular calcification and arterial stiffening play important contributory roles. The pathophysiology of CAD in ESKD is distinct from the general population. ESKD patients is typically have diffuse multi-vessel involvement with increased calcification that involves both intimal and medial layers of the arterial wall. There is a complex interplay between an increased burden of traditional Framingham risk factors and exposure to non-traditional risk factors including chronic inflammation and dialysis per se. Established treatments for CAD risk factors including cholesterol lowering with statin therapy have attenuated effects and ESKD patients also have worse outcomes after revascularisation. Recent trials such as the Canakinumab Anti-Inflammatory Thrombosis Outcomes Study (CANTOS) have established that direct modulation of inflammation improves CVD outcomes in the general population, which may prove to be a potential attractive therapeutic target in ESKD patients. Multiple retrospective observational studies comparing mortality outcomes between haemodialysis (HD) and peritoneal dialysis (PD) patients have been inconclusive. Randomised trials on this issue of clinical equipoise are clearly warranted but are unlikely to be feasible. Screening for stable CAD in asymptomatic ESKD patients remains a clinical dilemma which is unique to chronic dialysis patients being assessed for kidney transplantation. This has become particularly relevant in light of the recent ISCHEMIA-CKD trial which demonstrated no difference between optimal medical therapy and revascularisation upon CVD outcomes or mortality. The optimal strategy for screening is currently being investigated in the ongoing large international multi-centre CARSK trial. Here we discuss the pathophysiology, risk modification, treatment, screening and future directions of CAD in ESKD.

HEART and TIMI Scores Predict Severe Coronary Atherosclerosis in Patients With End-Stage Renal Disease

Objectives History, EKG, age, risk factors, and troponin (HEART) and thrombolysis in myocardial infarction (TIMI) risk calculators have been validated to predict the risk of subsequent acute coronary syndromes and in some studies, severe coronary atherosclerosis in patients with a concerning clinical history. Their performance in patients with end-stage renal disease (ESRD), a population with a high pretest probability for the condition, is unknown. We aimed to determine whether HEART and TIMI scores can predict severe coronary atherosclerosis in patients with end-stage renal disease (ESRD). Methods A single-center retrospective cohort of admitted patients aged 18 years or older with ESRD on dialysis who underwent coronary angiography during admission (November 2010 to December 2017) was retrospectively reviewed. The outcome of coronary angiography was compared with the calculated HEART and TIMI scores at the time of presentation. Receiver operating characteristics and logistic regression models were used to determine optimal score cutoffs, score usefulness, and associations between outcomes, scores, and patient characteristics. Results Among 231 patient encounters, the mean HEART and TIMI scores were 6±2 and 3±1 points, respectively. Patients with diabetes mellitus, those 65 years old and older, and those reported to have angina pectoris were more likely to show severe coronary artery disease (CAD) lesions. Optimal score cutoffs for determining severe coronary lesions were between six and seven (area under the curve (AUC)=0.754, confidence interval (CI): 0.682-0.826) and between three and four (AUC=0.716, CI: 0.640-0.792) for the HEART and TIMI scores, respectively. Conclusion Similar to the general population, HEART and TIMI scores can predict severe coronary atherosclerosis in the complex ESRD population.

The pathophysiology and management of vascular calcification in chronic kidney disease patients

INTRODUCTION

Vascular calcification (VC) which is the pathological mineral deposition in the vascular system, predominantly at the intimal and medial layer of the vessel wall, is an important comorbidity in patients with chronic kidney disease (CKD) leading to significant morbidity and mortality while necessitating appropriate treatment. Our review aims to provide an in-depth analysis of the current understanding of VC.

AREAS COVERED

In this review, we first discuss the pathophysiology of VC in CKD patients, then we explain the methods to predict and assess VC. Afterwards, we provide the currently available as well as the potential therapeutic approaches of VC. We finally discuss our understanding regarding the current situation surrounding VC in our expert opinion section.

EXPERT OPINION

Predicting, assessing and treating VC is crucial and the future advances in the field of research surrounding VC will potentially occur in one or more of these three areas of clinical management. There is a current lack of evidence and consensus regarding specific therapeutic options for alleviating VC and this situation may not necessitate VC to be determined, detected, and documented before the available options are implemented. Regardless, the prediction and assessment of VC is still important and requires further improvement together with the developments in therapeutic alternatives. The future has the potential to bring better research which would guide and improve the management of this patient group. A more specialized approach consisting of targeted therapies and more tailored management plans for patients with CKD and VC is on the horizon.

Comparison of revascularization with conservative medical treatment in maintenance dialysis patient with coronary artery disease: a systemic review and meta-analysis

Background

The primary cause of death among maintenance dialysis patients is coronary artery disease (CAD). However, the best treatment plan has not yet been identified.

Methods

The relevant articles were retrieved from various online databases and references from their inception to October 12, 2022. The studies that compared revascularization [percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)] with medical treatment (MT) among maintenance dialysis patients with CAD were selected. The outcomes evaluated were long-term (with a follow-up of at least 1 year) all-cause mortality, long-term cardiac mortality, and the incidence rate of bleeding events. Bleeding events are defined according to TIMI hemorrhage criteria: (1) major hemorrhage, intracranial hemorrhage or clinically visible hemorrhage (including imaging diagnosis) with decrease of hemoglobin concentration ≥5 g/dl; (2) minor hemorrhage, clinically visible bleeding (including imaging diagnosis) with a drop in hemoglobin of 3-5 g/dl; (3) minimal hemorrhage, clinically visible bleeding with hemoglobin drop <3 g/dl. In addition, revascularization strategy, CAD type, and the number of diseased vessels were considered in subgroup analyses.

Results

A total of eight studies with 1,685 patients were selected for this meta-analysis. The current findings suggested that revascularization was associated with low long-term all-cause mortality and long-term cardiac mortality but a similar incidence rate of bleeding events compared to MT. However, subgroup analyses indicated that PCI is linked to decreased long-term all-cause mortality compared to MT but CABG did not significantly differ from MT in terms of long-term all-cause mortality. Revascularization also showed lower long-term all-cause mortality compared to MT among patients with stable CAD, single-vessel disease, and multivessel disease but did not reduce long-term all-cause mortality among patients with ACS.

Conclusion

Long-term all-cause mortality and long-term cardiac mortality were reduced by revascularization in comparison to MT alone in patients undergoing dialysis. Larger randomized studies are needed to confirm the conclusion of this meta-analysis.

Cardiovascular outcomes of transradial versus transfemoral percutaneous coronary intervention in End-Stage renal Disease: A Regression-Based comparison

Background

Limited data is available on the comparison of outcomes of transradial (TR) and transfemoral (TF) access for percutaneous coronary intervention (PCI) in patients with end-stage stage renal disease (ESRD).

Methods

Online databases were queried to compare cardiovascular outcomes among TR. and TF in ESRD patients. The outcomes assessed included differences in mortality, cerebrovascular accidents (CVA), periprocedural myocardial infarction (MI), bleeding, transfusion, and periprocedural cardiogenic shock (CS). Unadjusted odds ratios (OR) were calculated using a random-effect effect model.

Results

A total of 6 studies including 7,607 patients (TR-PCI = 1,288; TF-PCI = 6,319) were included. The overall mean age was 67.7 years, while the mean age for TR-PCI and TF-PCI was 69.7 years and 67.9 years, respectively. TR-PCI was associated with lower incidence of mortality (OR 0.46 95 % CI 0.30–0.70, p < 0.05, I2 0.00 %), bleeding (OR 0.45 95 % CI 0.29, 0.68, p < 0.05, I2 3.48 %), and transfusion requirement (OR 0.52 95 % CI 0.40, 0.67, p < 0.05, I2 0.00 %) (Fig. 1). There were no differences among TR-PCI and TF-PCI for periprocedural MI, periprocedural CS, and CVA outcomes.

Conclusion

TR access was associated with lower mortality, bleeding, and transfusion requirement as compared to TF access in patients with ESRD undergoing PCI.

Plaque progression: Where, why, and how fast? A review of what we have learned from the analysis of patient data from the PARADIGM registry

Ischemic heart disease is the most common cause of mortality worldwide. The pathophysiology of myocardial infarction relates to temporal changes of atherosclerotic plaque culminating in plaque rupture, erosion or hemorrhage and the subsequent thrombotic response. Coronary computed tomographic angiography (CCTA) provides the ability to visualize and quantify plaque, and plaque progression can be measured on a per-patient basis by comparing findings of serial CCTA. The Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry was established with the objective of identifying patterns of plaque progression in a large population. The registry comprises over 2000 patients with multiple CCTA scans performed at least two years apart. Unlike previous CCTA registries, a semi-automated plaque quantification technique permitting detailed analysis of plaque progression was performed on all patients with interpretable studies. Since the registry was established, 19 peer-reviewed publications were identified, and all are reviewed and summarized in this article.

Blood and Salivary Inflammatory Biomarkers Profile in Patients with Chronic Kidney Disease and Periodontal Disease: A Systematic Review

Introduction: Periodontitis is the most prevalent inflammatory disease worldwide. Its inflammatory levels spread systemically, which can be associated with chronic kidney disease. Biomarkers have the potential to diagnose and correlate periodontitis and chronic kidney disease, helping to monitor systemic inflammation. Thereby, this study aimed to analyze the association between chronic kidney disease and periodontitis by conducting a biomarker analysis on blood and saliva. Material and methods: An electronic search through PubMed/MEDLINE, EMBASE, and Web of Science databases was conducted to identify clinical studies published in the last ten years, with no language restrictions. Twelve articles met all the inclusion criteria, two randomized controlled trials, one cohort study, and nine observational studies. Results: The studies included a total of 117 patients for saliva biomarkers, with a mean age of approximately 57 years old, and 56.68% of the subjects were female. After analyzing all the included studies, it was possible to verify the following biomarkers assessed: CRP, WBC, fibrinogen, IL-4 and -6, cardiac troponin T, NOx, ADMA, albumin, osteocalcin, cystatin C, PGLYRP1, cholesterol, HDL, LDL, triglycerides, and hemoglobin. Conclusion: A direct cause–effect association between periodontitis and CKD could not be established. However, it was possible to conclude that there was a correlating effect present, through the analyzed biomarkers.

Vascular Calcification in Chronic Kidney Disease: Distinct Features of Pathogenesis and Clinical Implication

Chronic kidney disease (CKD) is associated with a higher prevalence of vascular calcification (VC) and cardiovascular disease. VC in CKD patients showed different pathophysiological features from those of the general population. The pathogenesis of VC in CKD is a highly organized process, and prior studies have suggested that patients with CKD have their own specific contributors to the phenotypic change of vascular smooth muscle cells (VSMCs), including uremic toxins, CKD-mineral and bone disease (CKD-MBD), inflammation, and oxidative stress. For the diagnosis and monitoring of VC in CKD, several imaging modalities, including plain radiography, ultrasound, and computed tomography have been utilized. VC in CKD patients has distinct clinical features and implications. CKD patients revealed a more intense and more prevalent calcification on the intimal and medial layers, whereas intimal calcification is predominantly observed in the general population. While a higher VC score is clearly associated with a higher risk of all-cause mortality and cardiovascular events, a greater VC score in CKD patients does not fully reflect the burden of atherosclerosis, because they have more calcification at equal volumes of atheromatous plaques. The primary goal of VC treatment in CKD is the prevention of VC progression, and the main management is to control the biochemical components of CKD-MBD. Cinacalcet and non-calcium-containing phosphate binders are the mainstay of VC prevention in CKD-MBD management. VC in patients with CKD is an ongoing area of research and is expected to advance soon.

Chronic elevation of cardiac troponin I predicts the extent of coronary disease in hemodialysis patients presenting with acute enzyme elevation

Introduction

Elevation of cardiac troponin I (cTn-I) is associated with coronary artery disease (CAD) in asymptomatic patients with end-stage renal disease (ESRD) receiving hemodialysis. We aim to investigate the diagnostic value of chronically elevated cTn-I in ESRD patients presenting with an acute rise in serum cTn-I levels.

Methods

We performed a retrospective analysis of 364 patients. Using coronary angiography, we correlated baseline elevation of cTn-I with the severity of CAD when hemodialysis patients present with acute symptomatic elevation in serum cTn-I.

Results

In hemodialysis patients presenting with a rise in serum cTn-I above baseline levels, 59% had severe CAD, and 17% had no angiographic evidence of CAD. Hemodialysis patients with severe CAD had significantly higher baseline cTn-I levels compared to patients with non-severe CAD or normal coronaries (p < 0.0001). Baseline elevation of cTn-I in the severe CAD group was correlated with the degree of CAD occlusion (r2 0.56, p < 0.0001), fitting a positive linear model. Furthermore, baseline cTn-I differentiates between patients with and without severe CAD with a test accuracy of 0.72 (95% CI, 0.69-0.75, p < 0.001). At a value of ≥0.2 ng/mL (cutoff for myocardial necrosis), the specificity of baseline cTn-I for underlying severe CAD was 0.95.

Conclusions

Elevated baseline cTn-I has good accuracy for anticipating more advanced angiographic CAD when hemodialysis patients present with a symptomatic rise in serum cTn-I above baseline levels. Baseline elevation of cTn-I can be used for cardiac disease risk management in hemodialysis patients presenting with symptoms suggestive of CAD.

American Indian chronic Renal insufficiency cohort study (AI-CRIC study)

BACKGROUND

Chronic kidney disease (CKD) is an increasing epidemic globally that is associated with adverse health outcomes including end stage kidney disease (ESKD), cardiovascular disease (CVD), and death. American Indians (AIs) have a higher prevalence of CKD than most other racial/ethnic groups, due in part to a high prevalence of type 2 diabetes. Other genetic and environmental factors not yet identified may also contribute to the disproportionate burden of CKD in AIs.

METHOD

We will establish 3 clinical centers to recruit AIs from the Southwest United States (US) to expand the Chronic Renal Insufficiency Cohort (CRIC) study. We will follow the current CRIC protocol for kidney and cardiovascular measures and outcomes, which include ambulatory monitoring of kidney function and the use of mobile health technologies for CVD sub-phenotyping, and compare the outcomes in AIs with those in other racial/ethnic groups in CRIC.

DISCUSSION

AI-CRIC will identify the role of various risk factors for rapid loss of kidney function among AIs of the Southwest US. In addition, to better understand the natural history of CKD and CVD in this high-risk population, we will identify unique risk factors for CKD and CVD progression in AIs. We will also compare event rates and risk factors for kidney and cardiovascular events in AIs with the other populations represented in CRIC.

The reliability and feasibility of non-contrast adenosine stress cardiovascular magnetic resonance T1 mapping in patients on haemodialysis

BACKGROUND

Identifying coronary artery disease (CAD) in patients with end-stage renal disease (ESRD) is challenging. Adenosine stress native T1 mapping with cardiovascular magnetic resonance (CMR) may accurately detect obstructive CAD and microvascular dysfunction in the general population. This study assessed the feasibility and reliability of adenosine stress native T1 mapping in patients on haemodialysis.

METHODS

The feasibility of undertaking rest and adenosine stress native T1 mapping using the single-shot Modified Look-Locker inversion recovery (MOLLI) sequence was assessed in 58 patients on maintenance haemodialysis using 3 T CMR. Ten patients underwent repeat stress CMR within 2 weeks for assessment of test-retest reliability of native T1, stress T1 and delta T1 (ΔT1). Interrater and intrarater agreement were assessed in 10 patients. Exploratory analyses were undertaken to assess associations between clinical variables and native T1 values in 51 patients on haemodialysis.

RESULTS

Mean age of participants was 55 ± 15 years, 46 (79%) were male, and median dialysis vintage was 21 (8; 48) months. All patients completed the scan without complications. Mean native T1 rest, stress and ΔT1 were 1261 ± 57 ms, 1297 ± 50 ms and 2.9 ± 2.5%, respectively. Interrater and intrarater agreement of rest T1, stress T1 and ΔT1 were excellent, with intraclass correlation coefficients (ICC) > 0.9 for all. Test-retest reliability of rest and stress native T1 were excellent or good (CoV 1.2 and 1.5%; ICC, 0.79 and 0.69, respectively). Test-retest reliability of ΔT1 was moderate to poor (CoV 27.4%, ICC 0.55). On multivariate analysis, CAD, diabetes mellitus and resting native T1 time were independent determinants of ΔT1 (β = - 0.275, p = 0.019; β = - 0.297, p = 0.013; β = - 0.455; p < 0.001, respectively).

CONCLUSIONS

Rest and adenosine stress native T1 mapping is feasible and well-tolerated amongst patients with ESRD on haemodialysis. Although rater agreement of the technique is excellent, test-retest reliability of ΔT1 is moderate to poor. Prospective studies should evaluate the relationship between this technique and established methods of CAD assessment and association with outcomes.

Biological variation of metabolic cardiovascular risk factors in haemodialysis patients and healthy individuals

Background

Maintenance haemodialysis (HD) is associated with a very high cardiovascular risk and the assessment of metabolic cardiovascular risk factors is essential for an adequate diagnosis and management. The aim of the study has been to estimate the biological variation (BV) of serum lipids, calcium, inorganic phosphorus, 25-OH vitamin D, C-reactive protein and plasma intact parathyroid hormone (PTHi) and total homocysteine, to evaluate whether HD alter the homeostatic set-point of these magnitudes.

Methods

Blood samples were collected from 18 HD patients in steady-state conditions, one per month during 6 months, and from 11 healthy volunteers at weekly intervals over 5 weeks. BV data were derived using CV-ANOVA.

Results

Within-subject coefficients of variation (CVI) and derived reference change values (RCV) estimated in HD patients were significantly higher than in healthy individuals for calcium (CVI =3.8% vs. 2.3%) (RCV =12.6% vs. 7.6%), inorganic phosphorus (13.1% vs. 8.0%) (RCV =38.7% vs. 30.1%) and PTHi (20.3% vs. 11.3%) (RCV =57.5% vs. 34.0%).

Conclusions

For calcium, inorganic phosphorus and PTHi, RCV derived from advanced disease-specific BV data is recommended for the management of bone-mineral disturbances in HD patients. For the rest of cardiovascular risk factors, the use of RCV derived from healthy individuals could be appropriate.